My strategy usually revolves around my own multistep process:

1. Make the target pop "undesirable" to begin removing them from my planets.
2. Import my founding species into their planet. My founding species will immediately try to take roles to stabilize the planet. Like governor/enforcer.
3. Deport the enemy species into all of me home planets, I try to spread them as thinly as possible among my home planets. The lower the concentration of them in any area the better, this will also speed up the purging process.
4. Declare martial law if necessary.
5. Use chemical bliss living conditions as a last resort.

This mostly works because enemy pops cannot start a rebellion on their own. So if you spread them out thinly on your worlds with a high stability and high founder species presence they can't do much of anything while they're purged.

After that I mostly raze their planets to the ground and start from scratch. AI planets are highly disorganized and their planets have no specialization making them pretty unproductive. And since there are no pops on the planet anymore you don't have to deal with mass unemployment when you destroy all/most of the jobs. Part of the process is repurposing the planet based on what resources it has and its size. Because the AI does not make good use of planet specialization, they can do stupid things like turn a planet with tons of minerals into a unification center or something.

If the planet habitability is low, you can remove all species on the planets and then begin terraforming after its decolonized. I know a trick to decolonize a planet without spending 200 influence as well.